<?php
/**
 * Minimal, committed-state connected-platform lifecycle collection.
 *
 * Test IDs, titles, URLs, selectors, custom code and visitor rows remain local.
 * Network transport belongs exclusively to connected-transport.php.
 *
 * @package abtestkit
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

define( 'ABTESTKIT_CONNECTED_TEST_REF_PREFIX', 'abtestkit_connected_test_ref_' );
define( 'ABTESTKIT_CONNECTED_COLLECTION_STATE_OPTION', 'abtestkit_connected_collection_state' );

/** Stable, non-autoloaded random reference; do not clear on reconnect. */
function abtestkit_connected_test_ref_record( string $test_id ) {
    if ( '' === $test_id || strlen( $test_id ) > 160 ) {
        return new WP_Error( 'abtestkit_connected_invalid_test' );
    }
    $key = ABTESTKIT_CONNECTED_TEST_REF_PREFIX . hash( 'sha256', $test_id );
    $record = get_option( $key, null );
    if ( null === $record ) {
        $ref = '';
        if ( function_exists( 'abtestkit_hosted_sync_get_state' ) ) {
            $sync = abtestkit_hosted_sync_get_state();
            $prior = $sync['records'][ hash( 'sha256', $test_id ) ]['test_ref'] ?? '';
            if ( is_string( $prior ) && 1 === preg_match( '/^test_[A-Za-z0-9_-]{43}$/D', $prior ) ) {
                $ref = $prior;
            }
        }
        if ( '' === $ref ) {
            $random = abtestkit_hosted_random_credential();
            if ( is_wp_error( $random ) ) {
                return $random;
            }
            $ref = 'test_' . $random;
        }
        add_option( $key, array( 'test_ref' => $ref, 'observed' => false ), '', 'no' );
        $record = get_option( $key, null );
    }
    if (
        ! is_array( $record ) ||
        ! is_string( $record['test_ref'] ?? null ) ||
        1 !== preg_match( '/^test_[A-Za-z0-9_-]{43}$/D', $record['test_ref'] ) ||
        ! is_bool( $record['observed'] ?? null )
    ) {
        return new WP_Error( 'abtestkit_connected_test_ref_unavailable' );
    }
    return $record;
}

function abtestkit_connected_mark_test_observed( string $test_id, array $record ) : bool {
    $record['observed'] = true;
    $key = ABTESTKIT_CONNECTED_TEST_REF_PREFIX . hash( 'sha256', $test_id );
    update_option( $key, $record, false );
    $saved = get_option( $key, null );
    if ( ! is_array( $saved ) || empty( $saved['observed'] ) || ( $saved['test_ref'] ?? '' ) !== $record['test_ref'] ) {
        abtestkit_connected_collection_gap( 'reference_write_failed' );
        return false;
    }
    return true;
}

function abtestkit_connected_collection_gap( string $code ) : void {
    update_option( ABTESTKIT_CONNECTED_COLLECTION_STATE_OPTION, array(
        'last_gap_at' => time(),
        'last_error_code' => sanitize_key( $code ),
    ), false );
}

/** An exact, privacy-minimised projection of a stored experiment. */
function abtestkit_connected_test_payload( array $test, string $evidence ) {
    $kind = sanitize_key( (string) ( $test['kind'] ?? '' ) );
    $goal = function_exists( 'abtestkit_pt_normalize_goal_for_display' )
        ? abtestkit_pt_normalize_goal_for_display( $test['goal'] ?? '' )
        : sanitize_key( (string) ( $test['goal'] ?? '' ) );
    $status = sanitize_key( (string) ( $test['status'] ?? '' ) );
    if (
        ! in_array( $kind, array( 'page', 'post', 'product', 'reusable_section', 'custom_css', 'custom_html', 'custom_javascript' ), true ) ||
        ! in_array( $goal, array( 'clicks', 'form', 'destination_url', 'scroll_depth', 'add_to_cart', 'purchase' ), true ) ||
        ! in_array( $status, array( 'draft', 'running', 'paused', 'winner', 'complete' ), true )
    ) {
        return new WP_Error( 'abtestkit_connected_unsupported_test' );
    }
    return array( 'kind' => $kind, 'goal' => $goal, 'status' => $status, 'evidence' => $evidence );
}

/** Queue one event without changing the merchant's committed local outcome. */
function abtestkit_connected_queue_test_event( string $name, string $test_id, array $test, string $ref, string $evidence = 'observed' ) : bool {
    $payload = abtestkit_connected_test_payload( $test, $evidence );
    if ( is_wp_error( $payload ) ) {
        abtestkit_connected_collection_gap( $payload->get_error_code() );
        return false;
    }
    if ( 'winner_declared' === $name ) {
        $winner = strtoupper( (string) ( $test['winner'] ?? '' ) );
        if ( ! in_array( $winner, array( 'A', 'B' ), true ) || 'statistical_decision' !== (string) ( $test['winner_basis'] ?? '' ) ) {
            return false;
        }
        $payload['winner'] = $winner;
        $payload['winner_basis'] = 'statistical_decision';
    }
    if ( 1 !== (int) get_option( ABTestKit_Connected_Outbox::SCHEMA_OPTION, 0 ) && current_user_can( 'manage_options' ) ) {
        ABTestKit_Connected_Outbox::install();
    }
    $installation = ABTestKit_Connected_Installation::get_or_create();
    $event_id = ABTestKit_Connected_Event::new_id();
    if ( is_wp_error( $installation ) || is_wp_error( $event_id ) ) {
        abtestkit_connected_collection_gap( is_wp_error( $installation ) ? $installation->get_error_code() : 'random_failed' );
        return false;
    }
    $event = array(
        'schema_version' => 1,
        'event_id' => $event_id,
        'installation_id' => (string) $installation['installation_id'],
        'event_name' => $name,
        'occurred_at' => time(),
        'plugin_version' => abtestkit_hosted_sync_plugin_version(),
        'test_ref' => $ref,
        'payload' => $payload,
    );
    $queued = ABTestKit_Connected_Outbox::enqueue( $event, time() );
    if ( is_wp_error( $queued ) ) {
        abtestkit_connected_collection_gap( $queued->get_error_code() );
        return false;
    }
    return true;
}

/**
 * Observe only registry state confirmed by a successful option write. Older
 * tests receive a baseline of their prior state, never a fabricated creation.
 */
function abtestkit_connected_collect_registry_change( array $before, array $after ) : void {
    if ( ! abtestkit_connected_platform_can_create_or_launch() ) {
        return;
    }
    $old = array();
    $new = array();
    foreach ( $before as $test ) {
        if ( is_array( $test ) && ! empty( $test['id'] ) ) {
            $old[ (string) $test['id'] ] = $test;
        }
    }
    foreach ( $after as $test ) {
        if ( is_array( $test ) && ! empty( $test['id'] ) ) {
            $new[ (string) $test['id'] ] = $test;
        }
    }
    foreach ( $old + $new as $test_id => $unused ) {
        $previous = $old[ $test_id ] ?? null;
        $current = $new[ $test_id ] ?? null;
        if ( is_array( $previous ) && is_array( $current ) && $previous === $current ) {
            continue;
        }
        if ( ! is_array( $previous ) && is_array( $current ) ) {
            abtestkit_connected_milestone_seed_new_test( (string) $test_id );
        }
        $record = abtestkit_connected_test_ref_record( (string) $test_id );
        if ( is_wp_error( $record ) ) {
            abtestkit_connected_collection_gap( $record->get_error_code() );
            continue;
        }
        $ref = (string) $record['test_ref'];
        if ( ! $record['observed'] ) {
            $baseline_test = is_array( $previous ) ? $previous : null;
            $initial_name = is_array( $baseline_test ) ? 'experiment_baseline' : 'experiment_created';
            $initial_test = is_array( $baseline_test ) ? $baseline_test : $current;
            if ( ! is_array( $initial_test ) || ! abtestkit_connected_queue_test_event( $initial_name, (string) $test_id, $initial_test, $ref, is_array( $baseline_test ) ? 'baseline' : 'observed' ) ) {
                continue;
            }
            if ( ! abtestkit_connected_mark_test_observed( (string) $test_id, $record ) ) {
                continue;
            }
            if ( ! is_array( $previous ) && is_array( $current ) && 'running' === (string) ( $current['status'] ?? '' ) ) {
                abtestkit_connected_queue_test_event( 'experiment_launched', (string) $test_id, $current, $ref );
            }
        }
        if ( ! is_array( $current ) ) {
            abtestkit_connected_queue_test_event( 'experiment_deleted', (string) $test_id, $previous, $ref );
            continue;
        }
        if ( ! is_array( $previous ) ) {
            continue;
        }
        $from = (string) ( $previous['status'] ?? '' );
        $to = (string) ( $current['status'] ?? '' );
        if ( $from === $to ) {
            continue;
        }
        $event_name = '';
        if ( 'running' === $to ) {
            $event_name = 'paused' === $from ? 'experiment_resumed' : 'experiment_launched';
        } elseif ( 'paused' === $to ) {
            $event_name = 'experiment_paused';
        } elseif ( 'complete' === $to ) {
            $event_name = 'experiment_completed';
        } elseif ( 'winner' === $to ) {
            $event_name = 'winner_declared';
        }
        if ( '' !== $event_name ) {
            abtestkit_connected_queue_test_event( $event_name, (string) $test_id, $current, $ref );
        }
    }
}

/** Bound upgrade reconciliation to 20 baselines per cron tick. */
function abtestkit_connected_reconcile_baselines() : void {
    if ( ! abtestkit_connected_platform_can_create_or_launch() ) {
        return;
    }
    $tests = get_option( 'abtestkit_page_tests', array() );
    if ( ! is_array( $tests ) ) {
        return;
    }
    $queued = 0;
    foreach ( $tests as $test ) {
        if ( $queued >= 20 ) {
            break;
        }
        if ( ! is_array( $test ) || empty( $test['id'] ) ) {
            continue;
        }
        $test_id = (string) $test['id'];
        $record = abtestkit_connected_test_ref_record( $test_id );
        if ( is_wp_error( $record ) ) {
            abtestkit_connected_collection_gap( $record->get_error_code() );
            continue;
        }
        if ( $record['observed'] ) {
            continue;
        }
        if ( ! abtestkit_connected_queue_test_event( 'experiment_baseline', $test_id, $test, (string) $record['test_ref'], 'baseline' ) ) {
            break;
        }
        if ( ! abtestkit_connected_mark_test_observed( $test_id, $record ) ) {
            break;
        }
        ++$queued;
    }
}